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Comments 129451 to 129500:

129451. Dan Pangburn at 01:45 AM on 21 May 2009
        It's the sun
        Patrick 412 For a possible explanation (which excludes a significant contribution from CO2 increase) of much of the temp rise during the 20th century see 371 (A recheck of the graph shows the start of the GSM runup to be closer to 1930 with a small rise to 1945). I am aware that TSI itself is not enough but global temps are very sensitive to cloud cover and clouds are sensitive to sunspots (Google cloud sunspot)so sunspot activity acting as a catalyst on clouds could well be the cause of most of the observed 20th century temperature rise. The Grand Solar Maximum combined with the PDO uptrend to produce the rapid rise starting about 1976. Since about 2002 PDO is in a downtrend and the sun hasn't been this quiet this long since 1913 ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/MONTHLY.PLT so it looks like the GSM has ended. The good news is that the huge thermal capacitance of the oceans will calm whatever happens.
129452. Dan Pangburn at 21:32 PM on 20 May 2009
        It's the sun
        Chris 403 I am sorry that you have trouble understanding my posts. I often make the mistake of assuming that others have my insight. Here are a few trends obtained ‘by eyeball’ off graphs of CDIAC-ORNL data. The numbers are all in ybp Downtrend 57,000 to 54,600 Uptrend 54,600 to 50,300 Downtrend 50,300 to 45,200 Uptrend 45,200 to 42,000 Downtrend 42,000 to 36,500 The shortest Milankovitch is about 23,000 years so there can be no significant coupling. If you are familiar with the concept of impedance mismatch you will understand this immediately. It is obvious that you have little knowledge of Control Theory. In Control Theory, feedback is a dimensionless number that is defined as the influence that the response has on the input to the control/plant (my use of the word stimulus was apparently misleading). As used in climate science, feedback usually has units that can not be normalized by being divided by energy input. Thus these climate science feedback values are not directly applicable in Control Theory. Sometimes in climate science, feedback is defined in a way indicating that it is unitless such as described at http://climatesci.org/2008/04/08/has-the-ipcc-inflated-the-feedback-factor-a-guest-weblog-by-christopher-monckton/. One reference which gives their definitions for use in both climate science and Control Theory is at http://www.answers.com/topic/feedback . To avoid ambiguity, I will use CT feedback when referring to it as always used in Control Theory as first described by Bode in 1945. However, the difference in meaning of feedback as used in climate science and CT feedback as used in Control Theory is not relevant to determining the sign of CT feedback. The trends, like the five listed above, prove that CT feedback was not then and can not now be significantly positive. When the IPCC says that the max temperature increase with doubling carbon dioxide level is 1.2 °C if there is no feedback, it doesn’t matter what definition of feedback they are using. (Remember that I think that this increase is too high and that most of it has already occurred). Your failure to recognize that the sign of CT feedback in earth’s climate can be determined using Control Theory (and paleo temperature data) is understandable considering your lack of understanding of Control Theory. It is easy to understand the concept of enhanced GW. But the observations are that GW does not get enhanced. Some have proposed that clouds change to cancel it. Control Theory with paleo temperature data proves that GW does not get enhanced.
129453. HaydenK at 15:18 PM on 20 May 2009
        Temp record is unreliable
        That is a nice article!That's because they are troposphere numbers. They should be like that. The trends are in agreement.Well, it is not new to me. But aside from that breaking news, are you familiar with Victoria Gotti? Victoria Gotti is in trouble. She isn't getting arrested or anything, but the mortgage on the castle Victoria Gotti lives in is about to get foreclosed on – putting the Mafia princess out of her home. Daughter to criminal royalty, John Gotti, the onetime head of the Gambino crime family, she married a mobster herself (surprise!) and they were able to purchase a lavish home close to Long Island. She is $650,000 behind, so she isn't likely to be able to keep it, and that is definitely out of the reach of quick payday loans. However, with a mortgage that size there will probably be no mortgage loan modification in the future for Victoria Gotti
129454. thingadonta at 14:16 PM on 20 May 2009
        It's the sun
        With regards to your comment, I would say it is a leap of faith to argue that human affairs and a trace gas is driving global warming to catastrophic global climate change, when human and geological history shows otherwise. More on human history and the sun: In contrast to Europe's middle ages, many ancient societies had the sun at the centre of their 'social affairs' (eg Egypt, Aztec etc), for reasons that are quite simple- changes in seasons, droughts, floods, seasonal crop yields etc etc were all directly related by whether or not the great ball in the sky was being favourable to their particular needs. If there was too much sun there would be drought, too little there would be flood etc, or so the thinking went. The sun was pretty much responsible for their longer term welfare. This largely explains sun worship that developed in many ancient cultures. A different kind of society developed in parts of the Middle East, Europe, and some other places, where the sun was relegated to a far more subordinate role. Human affairs would be controlled largely by bureaucrats, officials, and the existing social order, not the pie in the sky. Particularly in areas where the seasons and climate didn’t fluctuate a great deal, the role of the sun, naturally, was relegated. One of these areas was Europe, where the seasons are predictable and aspects of climate like rainfall is fairly uniform over the years, and where bureaucrats, and their influence, therefore got the better of things. Humans and human influences would control social affairs, not something as irrelevant as the sun. And one could argue that this is a natural development over the centuries in a continent where climate doesn’t vary much, but human needs and social affairs certainly do. And by no means would the sun be at the centre of things- humans and the existing social order- would be at the centre of social affairs. And so there was strong resistance to the idea that the earth revolved around the sun and that it, and human affairs, was subordinate to it, in much the same way that today there is resistance to the idea that the sun drives climate change and associated politics and ‘social affairs’. It is simply not in the traditional bureaucratic psyche of the western world to be favourable to the idea that the sun controls ‘human affairs’, and that bureaucrats and their influence, is irrelevant.
129455. Patrick 027 at 13:15 PM on 20 May 2009
        It's the sun
        thingadonta - There are reasons why people believe things that are not true, but the fact that it's possible to imagine a reason why people believe something does not make everything that people believe not true. To hold that changes in the sun are the dominant factor in the last several decades of climate change requires a leap of faith.
129456. thingadonta at 12:48 PM on 20 May 2009
        Models are unreliable
        There is a few points I would like to make regarding modelling (as i have worked in modelling for government). Most Government agencies use simplified models to describe and plan for the real world, because most see that as their job, to attempt to bring order amongst all the 'noise' that is out there. But most of these government agencies, and most of their models, are actually based on rather socialist-type assumptions, which eg reduce 'noise', to irrelevancies, and eg frequently rely on linear relationships, weakening away from an identified mean or dominant factor. The argument is complicated, but I would say that this is primarily why extreme forms of socialism fail-in the real world there is plenty of 'noise' which isn't 'noise', or irrelevant, or ‘linear-weakening-strengthening by a simple factor/set of factors’, at all. (One of the best non-linear examples I can think of is the element Iron in the periodic table, which causes stars to explode in supernovas-but that is another story). The models used in complex systems such as climate can be fundamentally flawed, in exactly the way the bank models were flawed in the financial crisis-modellers simply tell the decision makers/executives what they want to hear, and what the modellers want them to hear (giving themselves promotion and bonuses etc, and reducing the need for costly data gathering etc etc). Major assumptions are played down, and data which doesn’t suit is left out or relegated to 'noise' etc. The real world just doesn’t work like that. Wherever models determine policy these models can be dangerous ie 'weapons of data destruction', especially in any political context. There is alot more I could say on modelling, as I have worked in this field, but maybe another day.
129457. thingadonta at 12:43 PM on 20 May 2009
        It's the sun
        In the middle ages, various officials, bureaucrats etc could not accept the idea that the earth is relegated to sub-ordinance to the sun (ie the earth revolves around the sun, rather than the other way around), because it conflicted with everything they learnt in bringing order and direction to the world, and from a well-defined social hierarchy. Modellers, and those in government agencies today, I would argue also don’t like attributing the sun to climate change partly because it conflicts with their need to bring order to a disordered world, and makes them, and all of what they have learned and can influence, irrelevant. It relegates human influence (or human-induced global warming) irrelevant. I would contend that the same psychological processes regarding resistance to the sun’s influence is going on today, because officials, and governments, essentially don’t change psychologically. But the sun will eventually win the climate debate, just as it did in the middle ages, because eventually the data will become unequivocal.
129458. thingadonta at 12:42 PM on 20 May 2009
        Naomi Oreskes' study on consensus was flawed
        There is no scientific consensus on the causes of recent (~150 years) global warming amongst scientists. What there is, however, is a continuing distortion of the statistics representing scientific research and opinion. For one thing, one can't simply report the views of climatologists only, (who generally have a vested interest), but more importantly, this would leave out the greater fields under which climate science is a subset-e.g. earth history and solar science. If you include earth history (i.e. geology etc) and solar scientists etc etc, the figures for 'consensus' always become smaller. Take for example the idea 'that global warming creates more deserts'. Nice idea to do research on. Climatologists, who are naturally assumed to best answer such a question, then go and gather lots of data, project models, debate, discuss etc etc, and yet don't even bother to consult the past geological record. This would be like a lawyer arguing a case without reference to any case histories. The geological record indicates, that warm periods correspond to less deserts, which is not mentioned in the subsequent climatologist reports. An example is the drying of Africa during the onset of glacial (cooler) periods in the last ~5 Ma, which led to reduced rainforests and more savannah, and the consequent evolution of an upright ape on the savannah-the hominid line (that’s us). But according to the IPCC, Africa does the opposite-it is projected to get drier overall with projected warming, which means, according to the IPCC, we wouldn't even be here. The statistics and reporting of consensus regarding human-induced climate change has been distorted, similar to what went on in the Soviet Union in the past, eg something like "928 tractor factories were surveyed in the Soviet Union, with 75% supporting the Party's position that production has increased and living standards are better, and 25% are looking more into improving worker conditions, whilst none claim that things have got worse...etc etc". Or to take a more contemporary example, if you asked various USA banks a few years before the recent financial crisis what state their financials were in, what kind of answer do you think you would have got? The Oreskes report is a gross distortion. Here is a link to all 928 abstracts so you can check them for yourself-http://www.staff.livjm.ac.uk/spsbpeis/Oreskes-abstracts.htm- the vast majority of which are COMPLETELY NEUTRAL as regarding the question of human-induced climate change. Think of it another way, if you are studying squirrels, and want to do research, what better way than looking into how any climate changes might affect squirrel numbers, dung chemistry of whatever. Note, however, that in this context, there isn’t any 'position' taken on whether or not humans are causing climate change, (or even that it is occurring), something which such a study couldn't answer. The vast majority of the 928 abstracts fall into this 'neutral' category. To say that “none of the papers disagree with the consensus position” (i.e. human-induced global warming), is a gross distortion; a small percentage have come to stronger conclusions which question it, and a small percentage have come to stronger conclusions which support it (the relative proportions for both cases is difficult to put a figure on, because the data, by its very nature, is ambiguous), but the point is, the vast majority are not even attempting to answer the question.
129459. John Cross at 12:02 PM on 20 May 2009
        Does ocean cooling disprove global warming?
        Ian: Humm, I don't know why the difference in the depth of the ARGOs unless in the paper they are using a subset of the whole dataset. This link shows the data from the buoys around Australia. If you look as the data for each, it would appear that most are getting close to 2,000 m. Regards, John
129460. Patrick 027 at 10:25 AM on 20 May 2009
        It's the sun
        Other quick points about ice ages: The ~ 100,000 year cycle is the eccentricity cycle. It modulates the effect of the precession cycle (if/when the eccentricity is near zero, the precession cycle has little effect). The 100,000 year cycle actually varies over a longer period of time. The ~ 40,000 year cycle is the obliquity cycle, in which the tilt of the Earth's axis relative to the normal of the orbital plane varies a few degrees. Higher obliquity increases the amplitude of the seasonal cycle, and in the annual average, redistributes incident solar radiation from the tropics polar regions. The obliquity cycle has a greater effect at high latitudes than at lower latitudes (the increase or decrease in insolation at low latitudes is smaller than the compensatory opposite change at higher latitudes because the area at high latitudes with the opposite change is smaller than that at low latitudes (as I recall**); also the seasonal cycle caused by obliquity is much larger at higher latitudes). The ~ 20,000 year cycle is the precession cycle. It is actually the result of a somewhat longer cycle in the orientation of the tilt of the Earth combined with a longer period cycle in the orientation of the semimajor axis of the Earth's orbit. In the precession cycle, the Earth's axis wobbles about the normal of the Earth's orbit, so that the timing of the seasons shift around relative to the timing of perihelion and aphelion. The precession cycle has opposite effects in each hemisphere. Currently, perihelion occurs in Northern hemisphere winter (near the solstice) and Southern hemisphere summer, making the seasonal cycle larger in the Southern hemisphere and smaller in the Northern hemisphere. It also increases the annual average insolation in the Southern middle and high latitudes and reduces it in the Northern middle and high latitudes, because the increase in solar insolation at perihelion relative to aphelion is in proportion to the solar insolation recieved at the time of year at the latitude considered, so the increase in insolation at perihelion is closer to the winter solstice cannot fully make up for the decrease at aphelion when aphelion is closer to the summer solstice. The precession cycle could have a global average effect even if the Earth were symmetrical across the equator with differences between perihelion and aphelion alignments with the solstices verses alignments with the equinoxes. However, the Earth is not symmetical - in land distribution and topography, oceans and their currents, etc, so there can be a global average difference between when the perihelion occurs near the Northern hemisphere winter soltice verse the Southern hemisphere winter solstice. Note that the major ice sheet changes between glacials and interglacials of the Pleistocene have occured in the Northern Hemisphere; that aside, this also playes a role in the vegetation and seasonal snow feedbacks. Not that the Southern hemisphere doesn't have sea ice. Of course, the dominance of water at Southern midlatitudes means that even when orbital forcing tends to increase the seasons' amplitudes there, the seasonal variations might still be small... --------- Effects: The effects depend on the arrangments of continents and oceans, etc, the general climate state and other forcings, and the biological species present. Even when there are not glacial-interglacial variations, the precession cycle continues to have an effect on low-latitude monsoons (this is why the Saraha desert was significantly wetter several thousand years ago). There are thresholds involved... the forcing must at least reach some level to have some effect (such as producing lakes in the Sahara), and that may not happen each time the cycle repeats because of the eccentricity cycle. Ice sheets and glaciers can only form as fast as snow accumulates, but can melt and disintegrate faster. As solar insolation is redistributed over space and time, it is possible the global albedo may vary - for example, higher obliquity and winter perihelion may direct more sunlight onto snow and ice, reducing the total solar energy absorbed. Conceivably, sometimes the same pattern that would favor warming by deglaciation might actually cause some initial global cooling (?). When ice sheets form and grow, they thicken, and the surface elevation increases. Over time, isostatic adjustment occurs, but the ice surface elevation is still higher than the initial land surface elevation. This elevation causes the surface to be colder than it otherwise would be. Thus, in addition to the regional effect of albedo, it may be necessary to go beyond the threshold of forcing that allowed glaciation to start in order to actually cause deglaciation - however, melting and evaporation around the edges of an ice sheet will cause greater flow out of the higher middle and thin the middle that way. Also, if/when ice sheet loss is faster than isostatic rebound, the surface elevation will get lower than otherwise for the same thinning of the ice sheet. It may be the case that the first several Northern hemisphere glaciations of the last millions of years produced ice sheets that flowed faster for a given elevation gradient due to lubrication underneath from soil and loose rock/sediment. This faster flow would make the ice sheets thinner. Eventually this lubrication would be lost as successive glaciations scoured away the loose material. Thus later ice sheets could have grown thicker. It has been suggested that this is why, around 900,000 or 700,000 years ago (which one?), the dominant period in glacial-interglacial variations shifted to the longer 100,000 year cycle. Whether or not that is why, it is possible that the 100,000 year eccentricity cycle can dominate if conditions occur such that only 1 in 5 peaks or so in the precession cycle are able to pass the threshold that causes large deglaciation, as opposed to most or all.
129461. DeWitt Payne at 09:47 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        Re:#25, I have no responsibility to explain. It's not my job. However, since 2.3E22 J/year would correspond to a sea level rise of about 2.5 mm/year by itself, and I have seen no evidence of an acceleration in sea level during the 2001-2004 period it is likely that the OHC measurements are incorrect. That would seem to mean the Argo numbers are too high or the earlier XBT numbers are too low. Either way the overall rate of increase in OHC and corresponding radiative imbalance is reduced unless you postulate that there was an increasing cool bias over time in the XBT numbers, which seems rather strained. Smaller thermal expansion and greater ocean mass increase pre-2003 would also be more in line with the Cazenave et al 2009 numbers rather than the IPCC FAR estimates.
129462. Patrick 027 at 09:38 AM on 20 May 2009
        It's the sun
        Dan - you shoud also know that Gord thinks (as is infered from the way he uses the term 'perpetual motion machine') that any object that is warmer than 0 K (absolute zero) must be a perpetual motion machine because of the constant activity on the molecular scale. Well, to be serious, he just doesn't seem to believe that there is such activity on a molecular scale. Or maybe he does and just refuses to be logical about the consequences. By his logic, you would burn yourself if you ever walked by a functioning mirror, and thus, functioning mirrors are physically impossible.
129463. Patrick 027 at 09:28 AM on 20 May 2009
        It's the sun
        Dan, about Gord's comment 398: 1. http://www.ilovemycarbondioxide.com/ipcc_oven.html That's one of the most idiotic things I've ever seen. Gord and I both agree that the chicken will not heat itself up. But Gord insists (by analogy from his actual comments) that this implies that the mirror cannot reflect photons back to the chicken. If a chicken is placed inside a mirrored container (mirrored at the relevant wavelengths), it will not increase in temperature because of the photons that return to the chicken after leaving it. But, if a warm chicken is placed inside a mirrored container, or if it is wrapped in aluminum foil, the reflection of photons back to the chicken will keep the chicken from cooling off (Setting aside convection and conduction). Even if the chicken is not completely covered, it will cool at a slower rate than if it were left completely exposed to a cooler environment (it loses heat to a cooler environment because (setting aside convection and conduction) there is less radiant flux per unit area reaching the chicken from the cooler environment than there is leaving the chicken to the cooler environment; it is a net energy flow). If heat is being supplied to the chicken at some wavelength that can pass through the mirrors or foil, the chicken will reach an equilibrium temperature when the rate at which it radiates heat to the cooler environment equals the rate at which heat is supplied; if the chicken is less exposed to the cooler environment, it needs to get to a higher temperature in order to get the same heat energy per unit time radiated out into the cooler environment. What if the foil is replaced by a sheet of carbon that absorbs radiation from the chicken? If the chicken recieves heat by some form of energy that can pass through the carbon, then - assuming the sheet of carbon completely covers the chicken and is perfectly opaque (and is tight around the chicken - so it's surface area exposed to the cooler environment is approximately the same as the surface area of the chicken)- it must lose heat to the carbon at the same rate if in equilibrium. But in equilibrium, the carbon must also lose heat at the same rate to the cooler environment. The equilibrium temperature of the carbon sheet will be the same (or approximately so) as the temperature of the chicken when the chicken is completely exposed. The chicken must be at an even higher temperature in order to lose heat to the carbon sheet. If the carbon sheet does not completely cover the chicken, the chicken's equilibrium temperature will drop the more it is exposed. If additional layers of carbon sheet are added, each raises the equilibrium temperature of all layers inside. This works both for radiation and for convection and conduction - additional sheets do not do much more to stop convection but they increase the distance through which heat must conduct to reach the outermost surface, and the rate of heat conduction per unit area is proportional to the temperature variation per unit distance. This is how winter coats work - they slow the loss of heat by conduction, convection, and radiation, from your skin to the environment, for a given temperature difference between your skin and the environment; thus, if your skin is heated at the same rate by your metabolism, it will rise to a higher temperature before it loses heat at the same rate to the environment when that heat must get through your coat. ------ Gord also mentions feedbacks purely between radiant fluxes and temperature. These do exist, but are not generally considered as 'climate feedbacks' - they are included in the the 'zero feedback climate response'. What are considered as feedbacks to the zero feedback climate response include changes in the tropospheric lapse rate**, and changes in composition and phase - humidity and clouds, dust, etc, snow and ice and anything else affecting the albedo of the surface, etc, and their arrangement relative to solar radiation and temperature distribution. The zero feedback climate response is understood to be the temperature response (including how it reacts to itself by changes in radiation with emissivity and absorptivity, scattering and reflectivity held constant****) with the arrangment of humidity, clouds, and the tropospheric lapse rate** in space and time (annual and daily cycles, internal variability) artificially and unrealistically held constant. **** at least in so far as optical properties are a function of composition and physical phase. Optical properties also vary due to temperature itself, but the change in optical properties due to a moderate-size temperature change are small compared to the variation over height...
129464. Patrick 027 at 08:48 AM on 20 May 2009
        It's the sun
        Actually, in my tangible analogy, it doesn't matter how thick the rods are if they are of constant thickness along their whole lengths.
129465. chris at 06:56 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        re #24 Certainly the climate is completely deterministic. The question is whether we can "measure" its parameters absolutely. The answer is usually no. After all 2 years ago the evidence indicated that the oceans were cooling quite significantly in the period 2003 to mid 2006. Shortly afterwards it was discovered this measure was an error due to bias in a section of the Argo floats. A reassessment indicated that oceans weren't cooling at all, but that there was still an incompatibility in the direct ocean heat measure and the ocean heat budget determined from a fuller analysis of heat and sea level rise. More recently these incompatibilities seem to have been resolved: the oceans are still continuing to take up heat. So there is obviously some uncertainty in the assessment of ocean heat content. If this is a consequence of random error in the measurement, we’ll certainly have more confidence in long term trends compared to short term trends. 30 years may be arbitrary. But I gave trends during the period 1970-2008 (Levitus et al. specified this long term trend), 1985-2008 and 2002 to 2008. These all show ocean heat uptake at a rate consistent with projections from models. And if we are going to assert absolute confidence in our measures of the deterministic climate and the changes in its parameters, we should ask not only why the oceans haven’t taken up much heat in the period 2003-2008, but why they took up so much heat (2.3 x 10^22 J per year – nearly 6 times the long term trend) during the period 2001-2004…..and essentially no heat in the period 1997-2001…or 1985-1990…. Either that’s all a true measure of the deterministic climate (in which case please explain!), or the long term trend in response to enhanced radiative forcing is overlaid by noise due to a level of inaccuracies in the measurements (or inadequate sampling). I think there has to be quite a bit of the latter....
129466. DeWitt Payne at 05:21 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        re: #22, But in a system with long term persistence, which is not an unreasonable assumption for climate, there is no reason to believe longer term trends are any more or less significant than shorter term trends. Measurement error has a random component. The climate at whatever time scale doesn't. It is completely deterministic even if it isn't predictable. There is no evidence I know of that there is a bright line between climate and weather. Thirty years is completely arbitrary. Even then it only means something if you restrict yourself to looking at separate thirty year blocks. Invoking natural variation is a double edged sword. The more you allow, the less certain are projections of future climate.
129467. Ian Forrester at 05:15 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        Ron and John Cross, I found a report which gives the following percentages for depth of ARGO floats: (as of 2008) 4000 (11%) could go to 1500 m 6000 (17%) could go to 900 m 13000 (38%) could go to 500 m 12000 (34%) could go to 10 m ftp://ftp.gfdl.gov/pub/ysc/Global_OA/REV1/replies.pdf It looks like the response to reviewers comments for a budget or grant application. If these numbers are true then they are much less than what is commonly believed for deep diving buoys.
129468. Patrick 027 at 04:59 AM on 20 May 2009
        It's the sun
        (from chris: "Clearly enhanced atmospheric water vapour and enhanced CO2 doesn't "influence" the sun nor the Earth's orbital properties. So there's something fundamentally wrong with your application of engineering concepts to the climate system in that respect." ) That is a very important point. In my 'tangible analogy', one could have the sensors sending signals to control secondary heat sources or heat sinks seperate from those controlled 'manually'. Of course, in the climate system, some devices (CO2, CH4, etc.) have multiple knobs and inputs...
129469. Patrick 027 at 04:54 AM on 20 May 2009
        It's the sun
        "very strong evidence that the relationship between Temp and CO2 is linear." Well, maybe the relationship between temperature and radiative forcing from CO2 is nonlinear, then. Which does not necessarily imply the same for temperature response to CO2 as an external forcing, because the climate response to orbital forcing is complex. "If one applies enough input signals and analyses the output signals with respect to "rise times", "amplification or loss", "linearity and distortion" etc. you would be surprised how accurately one can determine the contents of the "black box"!" ... "This practice is commonly called "Reverse Engineering", a term most people probably have heard of before." So control theory in the context of climatology is called 'paleoclimatology' and 'observations', plus analysis. Okay. We have people who do that. Why do we need to call it by a different name. And why must we ignore what we know about the physics of the contents of the black box from other fields/kinds of research? Dan - It might be easier for me to understand your logic if you describe what you'd expect to see from your black box if there are positive feedbacks. "The idea that climate scientists appear to have which is that there are different feedbacks and they can have different response times is bogus." The known physics suggests otherwise. (If we have the ability to open up the black box and peek inside, why should we not allow ourselves that benifit?) A more tangible analogy: I have a mass that is supplied with heat by a heat source and is cooled by a heat sink. The mass has two rods attached to it, with sensors at the end that adjust the heat source in response to measured temperature. One is short and thick, made of aluminum, and the sensor at the end sends a signal to increase the heat source in response to an increase in temperature. One is long and thin, made of rubber, and it's sensor sends a signal to decrease the heat source in response to an increase in temperature. There is also a third sensor embedded in the mass that sends a signal to increase the heat source in response to an increase in temperature. The mass has a heat capacity C. What happens if you reduce the heat sink?
129470. Patrick 027 at 04:31 AM on 20 May 2009
        It's the sun
        "Referring to the multi million year long Ordovician ice age as a “cold snap” is strange. " It was a snap compared to the later Paleozoic cold period and the recent Cenozoic cold period (that we are still in). That's all I meant by 'snap' in that context. As to how intense it was, I'm not sure.
129471. chris at 03:46 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        re #17 and #20 1. The trend in upper ocean heat content is around 0.4 x 10^22 J per year during the period 1970-2008, and 0.6 x 10^22 J per year from 1985 to 2008 in the Levitus data. According to Levitus the oceans have absorbed ~ 5.8 x 10^22 J of heat in the period end-2002 to end-2008 (I only bring this up since Pielke made a big issue of the ocean heat content increase expected in that period - 5.88 x 10^22 J!). 2. The recent evidence indicates a small continuing steric (warming) contribution to sea level rise during the last few years. This is likely (but not certainly) smaller than the long term trends (see 1) 3. However we know that it's generally unhelpful to make fundamental conclusions from a few years of measurements of parameters (e.g. surface temperature or ocean heart content) in the complex climate system. For example, inspection of the record of ocean heat content (see Figure 1 in Levitus 2009 or Figure 2 in John Cook's top article) shows other periods on the long rising trend of enhanced ocean heat content where the ocean heat content has been static or gone down a tad (the entire period between 1985-1993, for example). 4. What does that mean? Is it real...or due to measurement/sampling error .....or natural variation in the climate system (in this case perhaps involving significant redistribution of heat within the ocean)? Answer: we probably don't know. That's exactly why we prefer to inspect trends over rather longer periods where random error/variation (as opposed to systematic measurement bias) tends to average out.
129472. John Cross at 03:09 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        Ron: just as a point of clarification, the typical depth for the ARGO is deeper than 700. In 2006 (before the system was fully operations) 66% went to 1500m and about 1/2 went to 2000m. I would expect that this number has only increased. There are locations where shallower depths are used (the Mediterranean being one), but in general 2,000 is the standard. John
129473. DeWitt Payne at 03:06 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        The Cazenave paper linked in the article concludes thermal expansion averaged 0.3 mm/year for 2003-2008. That implies an annual OHC change of 0.3E22 J/year or 2.4E22 J total. While not zero, that's still a lot less than 5.8E22 Joules. So the question still is, why is the radiative imbalance lower than expected? Invoking natural variation is dodging the question. All variations have causes.
129474. Ron Cram at 02:20 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        Ian, not true. The Argo floats typically go down to 700m depth. There is no indication heat is being pushed down there. More rarely, even lower depths are sampled. Again, there is no indication heat is being pushed to the lower depths. If lower depths were warming, the ocean heat content estimates would calculate it.
129475. Ian Forrester at 00:09 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        Ron Cram, what you say is false since we don't know how much of the heat has been transferred to greater ocean depths.
129476. Ron Cram at 00:03 AM on 20 May 2009
        Does ocean cooling disprove global warming?
        Chris, I did not realize the full paper was available online. For others who wish to see it, it can be found at ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/grlheat08.pdf It appears to me the numbers used by Levitus are slightly different than those reported by Willis and Loehle. However, Levitus still shows no warming from 2004 to 2008. 2004 is about 14 x 10^22J and 2008 is about 14 x 10^22J. I do not understand your point at all, Chris. If there was a radiative imbalance, and in the absence of any other powerful impacts such as a major volcano, ocean heat content should have increased dramatically during those years. This concept is not difficult to understand.
        Response: This is precisely why I included volcanic eruptions in Figure 2. To show that even during periods where there are no volcanic eruptions, ocean heat shows natural variability. There are several periods in the long term warming trend where the trend flattens for several years, without volcanic influence. Ocean heat does not rise monotonically, it's a noisy signal.
        
        Which leads to my second point - when you are looking for a trend in a noisy signal, you do not compare one data point to another. It's a meaningless comparison. You need to statistically include all data points in that period to calculate a trend - simple examples of this are a least square linear fit or a moving average.
129477. chris at 20:32 PM on 19 May 2009
        It's the sun
        re #401 Dan, there is a muddle in your posts. And you're not reading my post correctly. I specifically stated that:

        "it's not just the glacial-interglacial transitions that are dominated by Milankovitch cyclesbut also the sub-transitions occurring largely within the glacial period which is what I suspect you're talking about (it would help if you were a little more specific!)."

        Why not be specific and highlight some specific periods. Which specific trends are you talking about? The reason that we know that it's not just the major glacial-interglacial transitions that are dominated by Milankovitch cycles, but also much of the slow transitions within (largely) the glacial periods, is because the ice core data has retained a faithful record of these. It's well established that the earthh's orbital parameters have three major cycles that have periods near 100,000 years (eccentricity), ~41,000 years (obliquity) and ~23,000 years (precession). Since these cycles are out of phase a rather complex insolation pattern accrues from the "summation" of the cycles which matches the ice core data quite well. As shown in a recent study, the ice core proxy temperature and 18-O signals in the cores can be Fourier transformed to pull out the dominant freequency components. The power spectrum shows clear strong peaks at 111,000, 41,000 and 23,000 years. In other words the temperatures are varying as a strong function of the intermixed contributions of the various Milankovitch cycles. So clearly the Milankovitch cycles are clearly not "far too long to influence trends". In fact the dominate the trends in the entire record. In these circumstances CO2 levels and their resultng feedbacks are a secondary consequence on the slowly varying insolation patterns driven by the earth's orbital properties. That in itself says very little about the magnitiude of the feedbacks which requires a rather more careful analysis. Kawamura et al (2007) "Northern hemisphere forcing of climate cycles in Antarctica over the past 360,000 years" Nature 448, 912-919. Your comments about Control Theory are just unsupported assertions. That's more "mantra" than science! A very obvious problem with your misapplication of control theory concepts to atmospheric physics is in your suggestion that engineering-style feedbacks and feedbacks in the climate system are similar in that "the response influences the stimulus" . But that's not quite right. When solar warming or changing insolation patterns during ice age cycles produece a water vapour and CO2 and albedo warming feedback, these "responses" don't "influence the stimulus". Clearly enhanced atmospheric water vapour and enhanced CO2 doesn't "influence" the sun nor the Earth's orbital properties. So there's something fundamentally wrong with your application of engineering concepts to the climate system in that respect. Of course there are engineering-style elements of feedbacks in the climate system. Enhanced CO2 results in a water vapour feedback that both enhances the warming resulting in enhanced water vapour and (very slightly) further enhanced CO2. There's nothing difficult to understand about that. Again we can observe this in the real world. As atmospheric CO2 levels rise so the atmopssphere warms and atmospheric water vapour levels rise. Following major eruptions the atmosphere undergos a transient aerosol-mediated cooling and water vapour levels drop amplifying the cooling. These are all well-characterized observations in the real world [***]. One can't argue away reality by assertion! [***]Santer BD et al. (2007) Identification of human-induced changes in atmospheric moisture content. Proc. Natl. Acad. Sci. USA 104, 15248-15253 Soden BJ, et al (2005) The radiative signature of upper tropospheric moistening Science 310, 841-844. Dessler, A.E., Z. Zhang, and P. Yang, The water-vapor climate feedback inferred from climate fluctuations, 2003-2008, Geophys. Res. Lett., 35, L20704 ...and so on...
129478. Gord at 19:10 PM on 19 May 2009
        It's the sun
        Regarding approximating a log function as a linear function over a short period of time. This is true, however, the long term cycles for CO2 and Temperature that the Vostok Ice core data shows (over about 400 Thousand Years)is also very strong evidence that the relationship between Temp and CO2 is linear. Ex. An audio amplifier is considered to be a "linear amplifier" if the output follows the input signal linearly. The amplifier may have a "Gain" and a "feedback loop" (or multiple feedback loops) but the transfer function relating the output and input has to be linear. This is part of Feedback and Control Theory and Practice used in Electrical Engineering. In fact, this is a common method used in Electrical Engineering lab exercises. You are given a "black box" with some circuitry inside which is unknown to the student. By applying an input signal and viewing the output, you can fundamentally describe the circuitry in the "black box". If one applies enough input signals and analyses the output signals with respect to "rise times", "amplification or loss", "linearity and distortion" etc. you would be surprised how accurately one can determine the contents of the "black box"! This practice is commonly called "Reverse Engineering", a term most people probably have heard of before. Linearity over multiple cycles combined with shorter term measurements that confirm linearity is very strong evidence that the relationship between Temp and CO2 is linear.
129479. Dan Pangburn at 16:51 PM on 19 May 2009
        It's the sun
        Chris 390: There is no muddling. Milankovitch cycles are far too long to significantly influence the trends. Trends remote from the glacial/interglacial and interglacial/glacial transitions are intentionally considered to avoid the issue. Chris 392: The insight that the Climate Science Community is lacking which is readily obtained using Control Theory is that atmospheric carbon dioxide has no significant influence on average global temperature. The consequences of failure to determine this is that a whole lot of people have been misled and freedom and prosperity are at risk. A lot of resources that could be spent usefully are being spent to investigate a non-problem. The use of Control Theory in assessment of whether the feedback from average global temperature is significant and positive is quite different (simpler) than the usual control problem which is to design a controller to accomplish some desired result. Engineers familiar with Control Theory quickly understand it. I have also observed that the use of the concept of “feedback” as successfully used in Control Theory when applied by engineers in designing real systems differs somewhat from the concept of “feedback” as applied in atmospheric physics and other elements of climate-related science. They are similar in that the response influences the stimulus. Engineering systems often have a feedback of one or more. What happens to the function 1/(1-F) as used in climate science when the feedback, F, equals 1? At low values of feedback there is no significant difference between the function used by climate scientists and the function used in engineering which is 1+F. The idea that climate scientists appear to have which is that there are different feedbacks and they can have different response times is bogus. Patrick 395, 396 Control Theory analysis shows that added atmospheric carbon dioxide has no significant influence on average global temperature. It does not get mired in the minutia of climate details because all factors are lumped together in ‘all of the factors that influence average global temperature’. All statements and assumptions that added atmospheric carbon dioxide has a significant influence on average global temperature lack substantiation. Referring to the multi million year long Ordovician ice age as a “cold snap” is strange.
129480. Gord at 16:12 PM on 19 May 2009
        It's the sun
        Dan Pangburn - Here is a funny cartoon that illustrates the positive feedback in the Greenhouse Effect physics. (it shows a reflective mirror and CO2 is not reflective, but it does demonstrate the absurdity of the positive feedback used in some of the Greenhouse Effect literature) Global Warming Physics Explained http://www.ilovemycarbondioxide.com/ipcc_oven.html
129481. Gord at 15:57 PM on 19 May 2009
        It's the sun
        Dan Pangburn - re: Your Post #384 Thanks for the link to the video at http://www.climate-skeptic.com/ Here are some more links that really describe a positive feed-back loop. The Greenhouse Effect "Absorption of longwave radiation by the atmosphere causes additional heat energy to be added to the Earth's atmospheric system. The now warmer atmospheric greenhouse gas molecules begin radiating longwave energy in all directions. Over 90% of this emission of longwave energy is directed back to the Earth's surface where it once again is absorbed by the surface. The heating of the ground by the longwave radiation causes the ground surface to once again radiate, repeating the cycle described above, again and again, until no more longwave is available for absorption." http://www.physicalgeography.net/fundamentals/7h.html ---- Tutorial on the Greenhouse Effect- University of Arizona "In this case, the Earth still gains 240 Watts/meter2 from the sun. It still loses 240 Watts/meter2 to space. However, because the atmosphere is opaque to infrared light, the surface cannot radiate directly to space as it can on a planet without greenhouse gases. Instead, this radiation to space comes from the atmosphere. However, atmospheres radiate both up and down (just like a fire radiates heat in all directions). So although the atmosphere radiates 240 Watts/meter2 to space, it also radiates 240 Watts/meter2 toward the ground! Therefore, the surface receives more energy than it would without an atmosphere: it gets 240 Watts/meter2 from sunlight and it gets another 240 Watts/meter2 from the atmosphere -- for a total of 480 Watts/meter2 in this simple model." http://www.lpl.arizona.edu/~showman/greenhouse.html ----- Somehow, they must have missed the fact that the Sun is the only energy source and what they describe is really a perpetual motion machine in a positive feed-back loop.
129482. Patrick 027 at 15:00 PM on 19 May 2009
        It's the sun
        The climate response to orbital forcings is a bit more complex than forcings like solar brightenning or externally-imposed CO2 forcing. If the climate is not cool enough, ice sheets will not form at all and there might not be any global average cooling. There are other things I could say about it but I have to take a break from this. Except one other important point: When discussin climate sensitivity to radiative forcing by CO2 and CH4, feedbacks that work through CO2 and CH4, important though they may be, are not actually counted toward the climate sensitivity to the CO2 and CH4 forcing - they add to the forcing. Climate sensitivity thus depends on context. Generally, feedbacks that are slower-acting than a change being considered may be treated as forcings. Radiative feedbacks can be described by their radiative 'forcing', but that is not to imply that they are not feedbacks. The total greenhouse effect may be a radiative forcing of about 155 W/m2 - but that includes water vapor and cloud LW effects. If only CO2 were removed, much of the water vapor forcing would also be revoved as a feedback.
129483. Patrick 027 at 14:24 PM on 19 May 2009
        It's the sun
        Snowbal Earth: What may have happened: In the Archean eon, methane had been building up in the atmosphere as a result of methanogens metabolizing the products of oxygenic photosynthesis (some methane can also be produced by oxydation of ferrous Fe as in hydrothermal activity; this could have been important in the origin of life). Oxygen reacted with ferrous Fe to produce ferric Fe - this removed Fe from the oceans (ferrous Fe is more soluble than ferric Fe), producing BIFs (banded iron formations - a present day source of iron for human industries). Oxygen could also react with some of the reduced carbon produced by life. However, methane in the atmosphere would eventually be dissociated by UV radiation. Because methane (unlike water) does not condense in the atmosphere, it mixes more easily into the upper atmosphere, and photolysis of this methane would enhance H escape to space. This ultimately left oxygen (from the photosynthesis that fed the methanogens) behind, so after enough had reacted with ferrous Fe, etc, it accumulated in the atmosphere. While CH4 was in the atmosphere, the warmth would have allowed some rate of chemical weathering to keep CO2 levels lower than otherwise. The increased oxygen in the atmosphere would cause CH4 levels to plumet. Cooling sets in, enhanced by positive snow/ice albedo feedback and water vapor feedbacks in particular. This slows the chemical weathering rate, allowing CO2 to build up from geologic emissions. But that is a slow process, and perhaps happen fast enough to prevent a complete freezer-over. A Snowball Earth But once the Earth is locked in ice with a high albedo, it takes much more CO2 to start a thaw than would have been sufficient to prevent the freeze. With the chemical weathering shut down and the oceans frozen over, geologic emissions to the air are free to build up over millions of years. Eventually, this warms the equatorial regions to just above freezing. The ice recedes. The climate is unstable when the ice line is at such low latitudes, and the ice rapidly recedes to higher latitudes, and then melts completely. With all the CO2 it took to start the thaw, the reduction of albedo now leaves the Earth in a sauna-like state. This may be the one kind of Earthly situation when chemical weathering is rapid. Although slow, there was some very weak water cycle during the Snowball, with evaporation from some ice surfaces and accumulation to produce glaciers, which, given millions of years, could cause some significant mechanical erosion. After the thaw, the high temperatures, the surface area of glacial debris, and the high CO2 level itself cause a rapid CO2 drawdown. Carbonate minerals are rapidly deposited in the ocean. The climate cools. Oxygen levels never decrease again to where they were in the Archean eon, but they are not as high as now. During the middle of the Proterozoic eon, there is enough oxygen to make the uppwer oceans oxic, but the deep oceans are still anoxic, and the effect of the oxygen on the sulfur cycle has made the deep ocean sulfidic, which reduces the solubility of a couple of key nutrients in the ocean that are involved in nitrogen fixation, perhaps slowing the evolution of life. Eventually the deep oceans become more oxic. But the oxygen levels are still not as high as in the Phanerozoic eon. Perhaps due to the breakup of the supercontinent Rodinia and the low-latitude concentration and arrangements of the continents, or maybe for some other reason?, (this might not be exactly the scenario proposed; but something like it has been suggested) methane might be produced at a greater rate. It can never become as abundant as it was in the Archean, but it can have an effect. A sudden change in the methane supply due to ecological interactions with ocean currents or... etc, could lead to a rapid reduction in methane in the air (continually lost to oxydation), and if the reduction is fast enough, cooling could set in faster than the resulting chemical weathering feedback could moderate it. Because of the continents being at low latitudes, the chemical weathering rate might be less sensitive to temperature changes. Sea ice forms and grows, and when it gets to low enough latitudes, complete freeze over is imminent. And so on... There are variations on this concept (the 'Slushball Earth', etc...). It is harder to have a Snowball Earth now because the sun has gotten gradually brighter over hundreds of millions of years. The coriolis effect also slowly weakens with time due to the tidal drag on the Earth's rotation that causes the moon to recede from the Earth. My understanding is that a larger coriolis effect (from faster rotation) would reduce the horizontal heat transports that occur for a given thermal gradient, allowing the pole-to-equator thermal gradient to be larger; this affects the sensitivity of the ice line to temperature changes. Biological evolution has important effects; I forget what but I have read that some change in biology may reduce the likelihood of a snowball Earth episode from occuring again. ------------------- A prolonged glaciation tends to reduce the chemical weathering rate, which is a negative feedback via CO2. However, lowered sea level may increase chemical weathering by exposing more land to erosion (but would carbonaceous sediment oxydize as well, increase geologic CO2 emission?). Also, glaciations cause mechanical erosion, and repeated fluctuations between glacials and interglacials may enhance the longer-term average chemical weathering rate because of the glacial debris that is left behind during warm periods. Sediment produced by mountain glacial erosion can of course be transported downhill to warmer levels where chemical weathering occurs. Land vegetation also affects erosion and chemical weathering. Geological factors can force the chemical weathering rate. The formation of mountain ranges at low latitudes in moist climates (Himalayas) will increase the chemical weathering rate (note also that geography plays a role in the precipitation rate on the Himalayas by affecting the monsoons). The erosion of some minerals is better at removing CO2 from the air than some other minerals. ------------ Ice ages: Milankovitch cycles do not involve much global annual average radiative forcing. What this orbital forcing does to a large degree is rearrange the distribution of solar heating over latitude and season. When this results in cooler summers, even if the winters are warmer (more snow?) but not too warm, then winter snow accumulation can linger longer into the summer. This has a regional and global albedo feedback, and when the snow doesn't completely melt in the summer, multiannual accumulations can form glaciers and ice sheets. The albedo feedback causes global cooling and can allow ice sheets to spread or grow more. Slowly, vegetation shifts, causing an additional positive albedo feedback. This may actually release CO2 into the air. Cooling of the oceans allows the oceans to hold more CO2 for a given atmospheric concentration, but this cannot draw the atmospheric concentration down so much. DEPENDING ON continental arrangments, ocean current configurations, etc, the change in climate may cause some combination of changes in ocean currents and changes in marine photosynthesis that cause the CO2 level to build up in the deep ocean. This doesn't necessarily involve any organic carbon burial in sediments (generally a slow process - part of the geologic portion of the carbon cycle), but could involve sinking organic matter from biologically productive regions of the upper ocean that oxydizes in the deep ocean. This adds CO2 to the deep ocean and takes it out of the upper ocean, which takes CO2 out of the air. When deep water upwells, that CO2 can be returned to the surface water and air. But if ocean circulation is reconfigured or if biological productivity is redistributed or increased (such as from fertilization from wind-blown dust due to climate change), a greater amount of CO2 can be stored in the deep ocean either by increasing the CO2 concentration or increasing the time it takes to reach upwelling areas from where it is added. There could be other possible mechanisms I haven't mentioned... So CO2 decreases as a result of cooling, and this also amplifies the cooling...
129484. Patrick 027 at 13:14 PM on 19 May 2009
        It's the sun
        Simple illustration: Suppose there is a radiative forcing change of 4 W/m2. Warming occurs. As warming occurs, several things happen: 1. water vapor increases - a positive feedback. 2. snow and sea ice area decrease - a positive feedback. 3. Large land ice sheet area decreases - a positive feedback. 4. the chemical weathering rate increases - a negative feedback that removes CO2 from the atmosphere. Water vapor tends to approach an equilibrium with temperature over a several days. Snow and sea ice might take a bit longer (it may depend on how well they initially preserve themselves by keeping the local temperature response less than proportional to the global average response and the equilibrium proportions). But I think both of these respond faster than the temperature itself responds to the forcing (because of thermal inertia - that is, the heat capacity of the oceans). Thus, these feedbacks amplify the equilibrium temperature fully by the time equilibrium temperature is reached. Now we have, after a few decades or so, a new equilibrium climate, with a full response of the atmosphere and upper ocean (aside from any other changes yet to occur). However, there are some areas of upwelling of water from the deep ocean that will still warm up - they will warm up as the warmth spreads from the warmer upper ocean through the deep ocean, to return in upwelling regions. Also, the land ice sheets take time to fully respond to a temperature increase. Thus, there is still warming in store. It may not be at a constant rate because of the idiosyncracies of how ice sheets shrink. But eventually, some new equilibrium is reached with the ice sheets in equilibrium with the temperature and the temperature of the deep ocean in equilibrium with the upper ocean and atmosphere, etc. But during all this time, chemical weathering has increased. The increase is, however, a small rate. As CO2 is removed from the air, the chemical weathering rate will slow both because of cooling and because there is less CO2 to remove, so it is a negative feedback that results in a reduced (but not zero) warming. Because it is slow, it does not not reach any such equilibrium before the other processes have gone to equilibrium. Hence, the temperature reaches a peak from the other positive feedbacks, and then slowly declines until this negative feedback (and the positive feedbacks' reaction to it) reaches equilibrium.
129485. Patrick 027 at 10:10 AM on 19 May 2009
        It's the sun
        Dan - another point before getting back to a simple illustration of climate sensitivity and feedback: You mentioned a lack of correlation of temperature to CO2 in recent times. Less than perfect correlation does not mean zero correlation. Over any given time period, even when there is cause and effect between two variables, one may find less or more correlation - there will be a scattering of correlations. This scattering will become large if the time periods are short. Why? 1. There can be other forcings. I think the effect of solar forcing has been minor compared to anthropogenic effects in total and especially in the last few decades, but I wouldn't say it is zero, and there could be some climate variation corresponding to shorter-term cycles (11 years, etc.). There is also the occasional volcanic eruption. Anthropogenic aerosol forcing (of various types, but adding up to a net cooling effect) has not been in constant proportion to anthropogenic greenhouse gas forcing; this could explain part of the lack of warming between ~1940 and ~1970. 2. There is internal (unforced) variability that originates from the climate system. El Nino years tend to be warmer than non-El nino years, for example. I don't know about the temperature relationship with the PDO (I suspect Spencer's analysis about cloud feedback is incorrect - I have looked at it and I didn't find it convincing). The AMO may contribute some multidecadal oscillation. Climate models do simulate such variability (maybe not the AMO specifically ??? - but in general, and they do reproduce at least some specific modes of internal variability, such as ENSO) - climate models, all of which produce a warming in response to a CO2 increase, also produce short term warming and cooling trends that have no correlation to CO2. CO2 has been a positive feedback in the glacial-interglacial variations. Going farther back in time, During the Phanerozoic eon (going back over 500 million years) the major 'ice-house' periods (including glaciations and also periods with less but still significant ice, such as now (Antarctica, Greenland) correspond to periods with lower CO2 (there had been some lack of correlation for the brief cold snap of the Ordivician, but newer work suggests that a sufficient drawdown in CO2 at that time could have or would have been caused by enhanced chemical weathering caused by the rise of the Appalachian mountains). I am not saying that other factors have not contributed, although sometimes they may contribute via CO2 as well as or instead of in addition to CO2.
129486. chris at 09:49 AM on 19 May 2009
        Does ocean cooling disprove global warming?
        re #14/15 Ron, it would help if you took a considered look at the data rather than just cutting and pasting what someone else says! I'm looking directly at Figure 1 of Levitus (2009): S. Levitus et al. (2009) Global ocean heat content 1955–2008 in light of recently revealed instrumentation problems Geophys. Res. Lett. 36, L07608 which is similar to Figure 2 in John Cook's top article on this thread. That's where the Joules come from! Pielke asserts that the end 2002/start 2003 to end 2008 heat accumulation must be 5.88 x 10^22 J...correct? That's what you wrote in your post #12. Levitus (2009) indicates that the upper ocean heat accumulation is almost exactly that. So there really isn't a problem is there. The observation matches the prediction. Of course the problem lies in Pielke's insinuation that our understanding of the greenhouse effect and the consequences of radiative imbalance is fundamentally flawed, by basing his analysis on an extremely short period of time in which the analysis of ocean heat content is being continually reassessed in the light of problems with the monitoring technology, and implying that (as John has just indicated), the real world must correspond in an idealised noise-free fashion, else the IPCC and climate science has got it all wrong!
129487. Patrick 027 at 09:48 AM on 19 May 2009
        It's the sun
        Thank you, chris. Gord - your comment 381 - "Atmospheric CO2 vs Earth Temperature During the Ice Ages The Ice Ages (Figure 7) shows the biggest variances (interpolating) for Temp is 13 deg C (+3 to -10)" I suspect this temperature is a regional one; the global average surface temperature variation between glacials and interglacials is somewhere around 6 deg C. On your other points: Within any sufficiently small interval, a 'nice' function (piecewise smooth) can be approximated by a line. As I just mentioned above somewhere, the logarithmic proportionality of radiative forcing to CO2 level is an approximation that does not apply indefinitely - specifically, at low enough CO2 level, the relationship will be closer to linear. -------------- The reason why: The general trend (applying to smaller peaks and valleys, across the multitude of individual absorption line peaks in the CO2 absorption band centered near 15 microns) is for absorption cross section (a cross section is the contribution to optical path length per unit mass (or moles); cross section per unit volume = optical path length per unit geometric length) to increase toward the center of the band near 15 microns. At sufficiently low levels, the effect is not even close to saturated at the tropopause level at most wavelengths, so increasing CO2 may have a nearly linearly proportional tropopause-level forcing. But eventually the wavelengths near 15 microns become saturated - the opacity becomes so great that there is very little temperature variation across any distance of significant transmissity, so further increases in opacity cannot much reduce the net radiative flux at that wavelength (a net radiative flux requires that there is some difference in radiant intensity coming from different directions - for LW radiation, some variation in temperature must be 'visible' at the wavelength being considered from a single location; when the opacity is large enough, temperature variations across a given geometric distance are essentially hidden from each other). However, outside this central portion of the absorption band, increasing CO2 still has significant LW forcing. The forcing becomes nearly logarithmically proportional to CO2 concentration, because for a given increase by some factor (such as by 2 - a doubling), the width of the interval of wavelengths of some level or greater opacity tends to increase by some nearly constant amount, as the width of the saturated interval increases, and the edges at which the opacity starts to become significant shift outward from the center. (Of course, blackbody radiation intensity will vary somewhat over wavelength, which will modify this picture just a little (not a large amount because their is not so much radiation intensity variation over the range of wavelengths encompassed by the CO2 absorption band. It will also be modified if the CO2 band expands into an area of greater overlap with an absorption band of some other substance - eventually, expansion of the CO2 band on the longer-wavelength side would run into greater opacity from water vapor. (PS such overlaps are taken into account in actually calculating the radiative forcing.). Because net air-to-air radiative transfer requires intermediate opacity - sufficient transmissivity for temperature variations to be visible to each other, but sufficient opacity for the layers of air to be visible from any distance - and because the region of intermediate opacity for CO2 corresponds to the sides of the band, in between the central saturated portion and the edges of significant opacity, and these regions merely shift outward from the center with increasing CO2 when in the logarithmic regime, the radiative effects of changing CO2 level are mainly on direct net radiative energy transfer between the surface and the air, from the air to space, and from the surface to space - EXCEPT where the spectrum of CO2 overlaps with water vapor or other agents - increasing CO2 will affect the radiative fluxes involving clouds, for example. -------------- Also, climate sensitivity (equilibrium global average surface temperature response per unit radiative forcing) is not expected to be invariant over temperature - but over a sufficiently small range it might be close to invariant. But for global cooling in particular, if we go beyond ice age cold, if we bring the 'ice line' into lower latitudes, the ice albedo feedback may reach a point at which the climate sensitivity actually becomes infinite. But not infinite to infinite temperature change - the infinite sensitivity just means that any infinitesimal negative radiative forcing would kick the climate over an edge and possibly cause complete freeze-over. -------------------------------
129488. Patrick 027 at 09:01 AM on 19 May 2009
        It's the sun
        More about models, parameterizations: http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/langswitch_lang/in http://www.realclimate.org/index.php/archives/2009/01/faq-on-climate-models-part-ii/langswitch_lang/sw --------------------- Other points I've made about radiation, the carbon cycle, ice ages, etc...: http://www.skepticalscience.com/Arctic-sea-ice-melt-natural-or-man-made.html#3186 http://www.skepticalscience.com/argument.php?p=12&t=392&&a=18#2944 http://www.skepticalscience.com/Is-Antarctic-ice-melting-or-growing.html#2768 http://www.skepticalscience.com/argument.php?p=12&t=392&&a=18#2926 (specifically the comments listed by number that are found here: http://www.realclimate.org/index.php/archives/2009/03/olympian-efforts-to-control-pollution/langswitch_lang/in ) http://www.skepticalscience.com/climate-sensitivity.htm#1724 ( in particular, http://blogs.abcnews.com/scienceandsociety/2008/07/tropical-storm.html http://blogs.abcnews.com/scienceandsociety/2008/07/global-warming.html#comments http://blogs.abcnews.com/scienceandsociety/2008/09/nature-is-not-a.html ) http://www.skepticalscience.com/climate-sensitivity.htm#1725 http://www.skepticalscience.com/climate-sensitivity.htm#1762 http://www.skepticalscience.com/climate-sensitivity.htm#1748
129489. Ron Cram at 08:56 AM on 19 May 2009
        Does ocean cooling disprove global warming?
        Chris, Pielke also writes: "The new Levitus et al. 2009 paper, while not discussing this issue, further confirms that global warming, using upper ocean heat content as the metric, has stopped, at least for now. Moreover, the rate of heating in the last 5 years falls significantly below the amount of heating predicted by the IPCC models, as shown in the above figure." http://climatesci.org/2009/05/18/comments-on-a-new-paper-global-ocean-heat-content-1955%E2%80%932008-in-light-of-recently-revealed-instrumentation-problems-by-levitus-et-al-2009/
        Response: I find Pielke's line of reasoning very peculiar. He has somehow become firmly convinced that ocean heat is not subject to any internal variability, despite the long term record showing otherwise.
129490. Ron Cram at 08:52 AM on 19 May 2009
        Does ocean cooling disprove global warming?
        Chris, Regarding relevance, these papers were also written by Loehle. If Craig comes and comments, I thought others here might want to know about some of this other published work. He has a fairly notable and growing publication record. Where are you getting Levitus's joules numbers from? Pielke writes: "Secondly, the authors did not covert their heat accumulation into Watts per meter squared. This can straightforwardly be completed for each year. Since 2004 in the Levitus et al analysis given above, the global average radiative imbalance is close to zero..." If a conversion would lead to zero radiative imbalance then there is roughly zero heat accumulation in joules. It looks to me like there is a mistake somewhere. It is either yours or Pielke's and given Pielke's remarkable record and reputation as a scientist, I think the mistake must be yours.
129491. chris at 08:23 AM on 19 May 2009
        It's the sun
        Re 371/373 Dan and Gord, the notion that climate scientists are deficient in their understanding as a result of limitiations in their “curriculum”, and more specifically that they are lacking crucial understanding of “Feedback Control Theory” (or “Control Engineering”, is extremely dubious! Perhaps you might suggest more specifically the insight that they are lacking and its consequences. One general and one specific point: 1. Scientists are not constrained by their “curriculum”. Most of what they learn comes from the real world practice of science, and the acquired knowledge and skills required to pursue their research endeavours, either first hand, or second hand (by collaboration). The notion that climate scientists lack a crucial expertise as result of their particular education is a silly one! Speaking personally my degrees were in Chemistry, but I now research in the area of Medical Biology and Biophysics. Pretty much everything I’ve learned and currently apply comes from studies and skills picked up (first hand) since my research education/training. It’s useful to use complex computational molecular dynamics simulations in my research, but since I consider it impractical to learn this field from the bottom up, I collaborate with expert practitioners in that subject. Likewise if I need to apply particularly complex statistical analyses, I tend to seek the help of appropriate experts….and so on. That second hand recruitment of appropriate skills within collaborative efforts underlies much of modern research. So scientists are certainly not stuck with what they learned from their educational “curriculum”! 2. More specifically, I wonder whether “feedback control theory” is a particularly useful field in relation to studying the climate. Perhaps you could say where you think its relevant applications lie in a more specific sense. If it is anything like the brief descriptions given here: http://en.wikipedia.org/wiki/Control_theory or here: http://en.wikipedia.org/wiki/Control_engineering …then one might question its appropriateness for climate science, and might even suggest that its use of the concept of “feedback” might differ from the concept of "feedback" as applied in atmospheric physics and other elements of climate-related science. For example, it’s very clear that the earth system is not subject to elements of control such as those described in control theory (if the Wikipedia pages give a suitable description). The Earth system is not “designed” to lie within certain ranges of parameters like temperature. In general these properties respond to contingent phenomena/events. When, in the Archeaen ages over 2 billion years ago, oxygen from early photosynthesising organisms oxidised all of the dissolved iron in the oceans and started to be leached into the atmosphere, it oxidised the dominant greenhouse gas of the time (methane) and earth’s temperature plummeted to the extent that there is evidence for a global freeze (“snowball Earth”). There were no “control elements” maintaining temperatures, and the feedbacks (largely an albedo one) was strongly positive. The tectonic events accompanying the opening up of the N. Atlantic at the nascent plate boundary was the likely cause of the massive release of greenhouse gases (methane and CO2) that caused the rapid global warming, ocean anoxia, and the associated extinctions at the Paleo-Eocene Thermal Maximum. Again there were no “control elements” (associated with feedbacks) that acted to maintain the preceding ambient temperature. The evidence indicates that changes in forcings (greenhouse gases, solar changes, volcanic activity) push the Earth’s temperature towards some new equilibrium level. In the case of the ice age cycles (considering glacial to interglacial transitions) enhanced insolation results in warming with a water vapour feedback that produces a re-partitioning of CO2 from the oceans to the atmosphere with an enhanced (warming) forcing accompanied by an enhanced water vapour feedback. The insolation changes are further enhanced by a positive albedo effect from ice sheet dynamics… There are some elements that might constitute a tendency towards homeostasis but these don’t require an understanding of control theory I suspect. If the earth becomes hotter the efficiency of weathering increases and this tends to increase the draw down of CO2 and provides a (very, very slow) negative (cooling) feedback. The presence of large concentrations of atmospheric oxygen tends to limit forcings from methane, although the release of large amounts of methane would be extremely problematic if the PETM is anything to go by…
129492. chris at 08:17 AM on 19 May 2009
        It's the sun
        Dan, you're muddling up some very simple phenomena in relation to the ice age cycles. In fact you've more or less answered your own dichotomy when you state: "Repeatedly during the last and previous glacial periods, a temperature increasing trend changed to a decreasing trend and vice versa. With knowledge of Control Theory it is recognized that this is not possible if there is net positive feedback from temperature unless it is triggered by an external stimulus that is more powerful than the feedback. The observed temperature trend changes show that any positive feedback effect must have been smaller than the external stimulus. That is, the external stimulus called the shots and net positive feedback, if any, was less significant." So what's the problem? We know very well that the primary driver of ice age cycles is the very slow cyclic variations in insolation patterns resulting from the slow cyclic variations in the orbital properties of the earth (Milankovitch cycles). The Milankovitch cycles result in changes in forcings that drive the transitions. The various positive feedbacks (slow ice sheet albedo and CO2 feedback and their accompanying fast water vapour feedbacks), amplify the effects of the insolation cycles (and "help" to transmit these globally - the evidence indicates that warming precedes CO2 rises in the Antarctic but follows CO2 rise in the Arctic). But that doesn't say anything about the magnitude of the feedbacks to rising CO2 levels which requires a rather more considered analysis. The climate sensitivity to CO2 (warming resulting from a doubling of atmospheric CO2 levels) is the temperature rise under conditions of constant insolation, and a great deal of empirical and theoretical analysis indicates that this is near 3 oC of warming per doubling of atmospheric CO2. Many of the changes in the ice age record that you are talking about involve rather small changes in atmospheric CO2 concentrations (20-40 ppm) which are expected to give rise to smallish temperature changes (including feedbacks) of 0.4 - 0.8 oC within a climate sensitivity of 3 oC. All your obervations indicate is that the ice age cycles (and most of the sub-transitions within the glacial periods) are dominated by the Milankovitch cycles, and the forcings resulting from insolation changes are larger than the small forcings resulting from raised CO2 levels (and vice versa for cooling). We knew that already! We also know that the observations from the ice cores are entirely consistent with a climate sensitivity somewhere around 3 oC. The ice core data tell us rather clearly that it's not just the main glacial-interglacial transitions that are dominated by Milankovitch cycles, but also the sub-transitions occurring largely within the glacial period which is what I suspect you're talking about (it would help if you were a little more specific!). The earth's orbital parameters are characterized by three major cycles having periods near 100,000 years, 41,000 years and 23,000 years. Since these cycles are out of phase a rather complex insolation pattern accrues from the "summation" of the cycles which matches the ice core data quite well. If you can find the following paper, have a look at Figure 2; it illustrates the extraction of the earth's orbital cycles by Fourier transformation of ice core data on proxy temperature and 18O variations. The power spectrum shows clear strong peaks at 111,000, 41,000 and 23,000 years, which matches the orbital cycle frequencies rather well: Kawamura et al (2007) "Northern hemisphere forcing of climate cycles in Antarctica over the past 360,000 years" Nature 448, 912-919. Apols for repeating this. I messed up the formatting in the previous version!
129493. chris at 08:14 AM on 19 May 2009
        It's the sun
        Dan, you're muddling up some very simple phenomena in relation to the ice age cycles. In fact you've more or less answered your own dichotomy when you state: "Repeatedly during the last and previous glacial periods, a temperature increasing trend changed to a decreasing trend and vice versa. With knowledge of Control Theory it is recognized that this is not possible if there is net positive feedback from temperature unless it is triggered by an external stimulus that is more powerful than the feedback. The observed temperature trend changes show that any positive feedback effect must have been smaller than the external stimulus. That is, the external stimulus called the shots and net positive feedback, if any, was less significant."Kawamura et al (2007) "Northern hemisphere forcing of climate cycles in Antarctica over the past 360,000 years" Nature 448, 912-919.
129494. chris at 07:28 AM on 19 May 2009
        Does ocean cooling disprove global warming?
        re #12 Ron, you're not really addressing the subject, but just dumping stuff (what's the relevance of tree rings to ocean heat content?). Let's take Pielke's assertion at face value: "Thus, according to the GISS model predictions, there should be approximately 5.88 * 10**22 Joules more heat in the upper 700 meters of the global ocean at the end of 2008 than were present at the beginning of 2003." O.K. fine. According to Levitus the end 2002 accumulated heat content was around 8.7 x 10^22 J and by the end 2008 it was around 14.5 x 10^22 J. That's around 5.8 x 10^22 J more heat in the upper 700 meters of the global ocean at the end of 2008 than were present at the beginning of 2003. So what's the problem? The accumulated heat seems to be right on the button in relation to Pielke's assertion of what the accumulated heat should be if the GISS model projection is required to be absolutely correct Of course like many measurements in the real world the data are somewhat noisy, and we are all aware of the problems (and the temptation!) of making interpretations based on observations over short periods of time. However one can hardly assert that there are problems with measurements compared to predictions when the measurements are almost exactly the same as the prediction.
129495. Ron Cram at 06:01 AM on 19 May 2009
        Does ocean cooling disprove global warming?
        Roger Pielke, the ISI highly cited climatologist referred to above, has blogged on a recent paper by Levitus regarding recent Argo instrumentation problems. He references a number of key papers. The biggest problem with the Levitus paper is that it does not even address the recent lack of warming. http://climatesci.org/2009/05/18/comments-on-a-new-paper... Pielke writes: "Thus, according to the GISS model predictions, there should be approximately 5.88 * 10**22 Joules more heat in the upper 700 meters of the global ocean at the end of 2008 than were present at the beginning of 2003. "For the observations to come into agreement with the GISS model prediction by the end of 2012, for example, there would have to be an accumulation 9.8 * 10** 22 Joules of heat over just the next four years. This requires a heating rate over the next 4 years into the upper 700 meters of the ocean of 2.45 * 10**22 Joules per year, which corresponds to a radiative imbalance of ~1.50 Watts per square meter. "This rate of heating would have to be about 2 1/2 times higher than the 0.60 Watts per meter squared that Jim Hansen reported for the period 1993 to 2003. "While the time period for this discrepancy with the GISS model is relatively short, the question should be asked as to the number of years required to reject this model as having global warming predictive skill, if this large difference between the observations and the GISS model persists.” Also, I contacted Craig Loehle to tell him his paper on ocean cooling was being discussed here. Perhaps he will comment. Also, his paper explaining why tree rings are not valid thermometers has been published. http://www.springerlink.com/content/45u6287u37x5566n/ Loehle and McCulloch also published a corrected 2,000 year temperature reconstruction correlated to temperature without using any tree rings. Interestingly, it did not confirm Michael Mann's Hockey Stick. http://scienceandpublicpolicy.org/images/stories...
129496. Dan Pangburn at 05:46 AM on 19 May 2009
        It's the sun
        Patrick 027 I have been searching for a metaphor to possibly provide insight into the relation between Climate Science and Control Theory. This is a poor one but will have to do until a better one comes along. Climate Science is like the complete definition of how to engineer a car. It defines everything in detail. For the car it would include the required size of gears, diameter of drive shafts, steering gear ratio, seat height, tire size, wire size, etc. etc. Control theory is like the patrolman who observes that the car is being driven too fast. The patrolman doesn’t need to know anything about how to design a car. He doesn’t need to know if some of the calculations may have contained errors. He doesn’t even need to know if there are factors making the car go that no one understands or even knows exist. In 386 you presented a huge list of details of what contributes to weather and by extension climate. I am not qualified to challenge that list, or determine if it is correct, adequately complete or even address it. In Control Theory, ALL of that gets lumped together into a box called ‘control/plant’ which is defined as ‘all factors that influence average global temperature’. The factors do not need to be defined in detail. They do not need to be correct. They do not even need to be known. By definition the ‘box’ in the Control Theory model contains ‘all factors that influence average global temperature’. The output in this Control Theory model is (by definition) average global temperature. Feedback is (by definition) the effect that average global temperature has on ‘all factors that influence average global temperature’. It is a trivially simple model but the science behind it is extremely powerful and proven in nearly endless successful applications. The planet itself is a perfect computer for weather and climate that, by definition, correctly accounts for all factors. The output from that computer is archived in ice cores and sediments. Using proxies, scientists have teased temperature anomalies (changes from a reference value) that are validated by being done by different people using different methods. For this assessment using Control Theory the data does not even need to be accurate in an absolute sense only reasonably representative in relative amplitude. Many sources report this data and a few are plotted from identified credible sources in my pdf file linked from http://climaterealists.com/index.php?tid=145&linkbox=true . The thing to be observed about this data is not the short term oscillations that average out but the long term trends of hundreds or even thousands of years. Now comes the crucial observation that may take an understanding of Control Theory. Repeatedly during the last and previous glacial periods, a temperature increasing trend changed to a decreasing trend and vice versa. With knowledge of Control Theory it is recognized that this is not possible if there is net positive feedback from temperature unless it is triggered by an external stimulus that is more powerful than the feedback. The observed temperature trend changes show that any positive feedback effect must have been smaller than the external stimulus. That is, the external stimulus called the shots and net positive feedback, if any, was less significant. The higher level of atmospheric carbon dioxide now results in changes to atmospheric carbon dioxide level being even less significant. If an AOGCM predicts otherwise it is either faulty or misused or both. It is unfortunate that most if not all Climate Scientists are unaware of Control Theory (it’s not in their curriculum). If they were knowledgeable in Control Theory they might not have made the egregious mistake of blaming Global Warming on added atmospheric carbon dioxide and misleading a whole lot of people. As far as one degree being significant, realize that it is one degree from the pre-industrial period and most of that has already occurred. I personally think that the influence of atmospheric carbon dioxide is much less than one degree and the temperature run-up at the end of the 20th century was a result of the Solar Grand Maximum combining with a PDO uptrend, both of which are now going the other way. If the politicians will just stay out of it, the free market will bring about acceptable solutions to the issues of finite supplies of fossil fuels.
129497. Patrick 027 at 04:54 AM on 19 May 2009
        It's the sun
        If Control Theory makes any sense at all, I don't get that from your posts (no offense), so I'm going to look it up elsewhere. (If there were no positive feedback, the temperature would not go up and down as much as it does.) "This is kind of vague but appears to expose a fundamental lack of understanding of how gases absorb photons. Perhaps it would help to study work by Dr. Jack Barrett" I skimmed it. From that: " The GCMs take feedbacks into account, such as the supposed positive feedback from extra warming caused by the absorption of radiation by extra water vapour. Such feedbacks have to be parameterised and although they may contribute a greater reality to the models, they also introduce extra uncertainties." No, the feedbacks are not parameterized; they are part of the climate model output. Parameterization is required for sub-grid scale processes... http://www.realclimate.org/index.php/archives/2007/01/the-physics-of-climate-modelling/langswitch_lang/sw --- But anyway, I have a really good understanding of radiative energy transfer in the atmosphere as it relates to bulk properties (emissivity and absorptivity, scattering cross section, etc, as a function of wavelength) - I have less detailed knowledge of the microscopic and quantum-mechanical mechanisms that give rise to this behavior, though I do understand the generalities (collision/pressure broadenning and doppler broadenning of line spectra, for example). My point was that, within some range of conditions, the tropopause level the radiative forcing by CO2 (integrated over all wavelengths and directions) can be approximated with a logarithmic relationship. This alone says little if anything of the relationship of the temperature response to radiative forcing. (PS - important (note this, Gord) - at sufficiently low CO2 levels, the relationship becomes more linear. Removal of all CO2 would not be an infinite negative radiative forcing - as I recall, I think it would be somewhere between -20 and -30 W/m2. With nearly 4 W/m2 forcing per doubling, this suggests that the logarithmic proportion must become inaccurate before 5 or 6 halvings.)
129498. chris at 02:20 AM on 19 May 2009
        Does ocean cooling disprove global warming?
        In an ideal world subject to ideal monitoring, the oceans shouldn’t lose heat while the climate system is in positive radiative imbalance. That seems to be the ideal to which DiPiccuo and Pielke are staking their claims on. That differs somewhat from the surface temperature record where year on year variation can incorporate true temperature decreases since year on year variation in the climate system can “overpower” the very marginal yearly temperature increase due to greenhouse forcing, and the surface temperature isn’t a measure of total heat content in the Earth system. So 2008 with a strong La Nina, and a solar minimum gives a real (and not unexpected) reduced surface temperature compared to the preceding years. However the expectation is that the radiative balance in 2008 is still in positive dis-equilibrium even if the excess radiative forcing is reduced somewhat. So the oceans should continue to absorb heat in 2008, but less strongly. Does that make sense? That’s how I see it… The question then is whether we occupy an ideal world, ideally monitored. In my opinion the latter is the origin of the uncertainties upon which DiPiccuo and Pielke play fast and loose! 1. There does seem to be uncertainties in the monitoring systems. I read the Levitus paper [*] (see fig 2 in John Cooks great summary above) last night, and this analysis, ‘though not the last world probably, does support the conclusion that ocean heat has continued to accumulate during the period from 2003, consistent with the analyses of steric (warming) and mass (glacial melt) contributions to sea level rise in recent papers. 2. The variation in the Levitus data (e.g. the very large jumps in ocean heat content from 2002-2004) is odd and may or may not be real. However if one considers the long term trend, that’s more likely a reasonable measure of the ocean heat uptake. Levitus annotate their Fig 1 (equivalent to John’s figure 2 above) with a trend (1970-2008) of 0.4 x 10^22 J per year. I worked out the trend from 1985-2008 is 0.6 x 10^22 J per year. 3. If the jumps in the data are real, then the most likely explanation might be the redistribution of ocean heat in the way that Dave Horton indicates (e.g. El Nino years excess warmth in the surface waters of large regions of the Pacific; La Nina years more surface heat taken down to the deeper oceans at the expense of more upwelling cold waters). The question then becomes whether these ocean currents take pools of cold or warm water outside the monitoring system, or the measuring of these pools becomes somehow biased as they redistribute in the oceans… 4. So there is some uncertainty over these issues. That’s obviously why we shouldn’t attempt fundamental conclusions on the basis of a few years worth of data! 5. Incidentally, it’s interesting to consider Pielke’s analysis of these issues, which I looked at in response to Ron Cram’s assertions on the preceding thread (see the link to Pielke’s web blog in his first post there). Pielke considers that the ocean cooling (which we now know very likely isn’t cooling at all!) casts grave doubts on our understanding of the greenhouse effect and the consequences of enhancing atmospheric greenhouse gas levels. He asserts that for “a requirement to NOT reject the IPCC claim for global warming“, various criteria of heat content should be satisfied. Thus, for example, the added upper ocean heat content must be (according to Pielke) at least 13 x 10^22 J by the end of 2008, and he asserts elsewhere that the upper oceans should have acumulated 5.88 x 10^22 J in the period end 2002 to end 2008 (if Hansens radiative imbalance GISS model projections are to be satisfied). He then proceeds to ridicule the modelling with a list of years 2003, 2004, 2005, 2006, 2007, 2008 each with “~ 0“ as their accumulated heat content! However if we compare Pielke’s proscriptions with the Levitus data, we find that the accumulated heat in the upper oceans is around 14.5 x 10^22 J at end 2008, and the accumulated heat in the upper oceans between end 2002 and end 2008 is close to 5.8 x 10^22 J. O.K. so we can quibble with this sort of “numerology“, and we accept that these data cannot be treated as being rock certain measures of reality. However the data actually conform to Pielke’s proscriptions, even though he was raising them in an attempt to trash the modelling.....which is interesting....
129499. Ian Forrester at 01:08 AM on 19 May 2009
        Does ocean cooling disprove global warming?
        John the information on the depth of ARGO bouys was obtained from this document: ftp://ftp.gfdl.gov/pub/ysc/Global_OA/REV1/replies.pdf I haven't a clue who any of the participants in the discussion are.
129500. John Cross at 23:38 PM on 18 May 2009
        Does ocean cooling disprove global warming?
        A couple of comment about ARGOS vs. XBT. An ARGOS buoy is a full CTD capable instrument as opposed to an XBT which is just temperature. This means that the CTD is recording temperature at a depth calculated from pressure. The XBT is transmitting temperature at a depth that is essentially preset, in other words the depth is found from the rate of sinking of the XBT which has been previously calculated. So it is using an estimated depth. While I have some experience with CTDs I have little with XBTs. however, my gut feeling is that the instrumentation in the CTD is of better quality than the BXTs. Ian, great link to the physics form. Interesting read. One comment, I think that most ARGOs go deeper than 700 meters. I thought that prior to sending out the data most would sink to about 2km than do a full CTD cast all the way up. Regards, John

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